Combination engine operated fuel pump and air pump

ABSTRACT

In the preferred form of the invention there is shown an air pump or air compressor having a housing attached to and driven by the action of a diaphragm fuel pump of the type well known in the art. The compressor is adapted to be connected to the fuel pump body which in turn is connected to the engine block in an area that will give ready access to the engine cam. Both the fuel pump and air compressor are driven by the fuel pump rocker arm through the engine cam whereby the rocker arm reciprocates a piston within an oil filled cylinder in the air compressor. A diaphragm is in turn operated through the reciprocation of the piston and the action of the oil in the cylinder, to draw air into and discharge air from a pumping chamber beneath the diaphragm.

United States Fate/m [1 1 Creager et a1.

FORElGN PATENTS OR APPLICATIONS 2/1948 Italy 417/388 [451 Nov 19, 1974272,374 6/1927 Great Britain 417/385 Primary Examiner -Williatn 1...Freeh Attorney, Agent, or Firm-Peter A1 Taucher In the preferred form ofthe invention there is shown an air pump or air compressor having ahousing attached to and driven by the action of a diaphragm fuel pump ofthe type well known in the art. The compressor is adapted to beconnected to the fuel pump body which in turn is connected to the engineblock in an area that will give ready access to the engine cam. Both thefuel pump and air compressor are driven by the fuel pump rocker armthrough the engine cam whereby the rocker arm reciprocates a pistonwithin an oil filled cylinder in the air compressor. A diaphragm is inturn operated through the reciprocation of the piston and the action ofthe oil in the cylinder, to draw air into and discharge air from apumping chamber beneath the diaphragm.

ABSTRACT 3 Claims, 3 Drawing Figures COMBINATION ENGINE OPERATED FUELPUMP AND AIR PUMP This invention relates to a combination fuel pump andair compressor and more particulary to an oil filled compressor integralwith a fuel pump which is operated by the fuel pump rocker arm. An oilpump on one side of a diaphragm acts to draw air into and pump air outof a pumping chamber. Prior art combination pumps or compressorsgenerally show the combination of a fuel pump and low pressure vacuumcompressor type pump but do not show a fuel pump combined with a highpressure compressor pump. Similar prior art devices do not include anoil filled cylinder on one side of the diaphragm. This is evidenced by.the prior art U.S. Pat. Nos. to Babbich et al, 2,139,346 and 2,189,526.

Under circumstances where the oil piston is reciprocated at high speedsit is necessary to provide a pumping cavity that allows for unrestrictedhigh speed movement of the diaphragm in the air pump chamber.Additionally, the diaphragm under high oil pressure must move smoothlyand completely in and out of the pump cavity to provide maximum air inand out of the pumping chamber though there is a very short distance andminimal movement and travel by the diaphragm. This action providesmaximum compression with a very short stroke.

Accordingly, an object of the present invention is to provide an aircompressor driven by the rocker arm of a fuel pump.

Another object of the present invention is to combine bolts throughholes 17 or by any other commonly used fastening means such as welding,or the like.

Rocker ann 18 having an auxiliary wear pad 20 thereon rides on camsurface 22 on the engine cam shaft. The operation of the rocker arm onthe engine cam as used to drive pumps is well known in the prior a fuelpump and air compressor to eliminate the need for a rocker arm and camdrive means, and a mounting area on the engine block that would berequired for a separate cam driven air pump.

Another object of the present invention is to provide an air compressorthat is self-priming and which prevents aeration of oil on the oil sideof the diaphragm to improve the operating characteristics of thecompressor.

Another object of the invention is to provide an im proved aircompressor that is adapted to be operated by an engine cam and whichincludes an oil filled reservoir or sump region.

These and other objects and advantages of the present invention willv beapparent from the drawings in which:

FIG. 1 shows the combination fuel pump and compressor having a commonrocker arm driven by the engine cam.

FIG. 2 is a sectional view of the compressor portion of the pump shownin FIG. 1.

FIG. 3 is a sectional view of a modified version of the bottom portionof the pump as shown in FIG. 2.

Referring now to FIG. 1, the combination fuel and air compressor isshown at 10 and includes a fuel pump 12 and air compressor 14. The fuelpump is of the diaphragm type well known in the prior art with the fuelpump per se not being considered as part of the invention other than inthe use of a common rocker arm to operate both the fuel pump and aircompressor. It is understood that either the fuel pump or air compressorcould work independently of each other, but in such a configuration theywould each require a separate rocker arm and cam as well as separatemounting areas on the engine block. The combination pump is attached tothe engine block by means of a-flange l6 and art as shown by thereferenced prior art patents.

Referring to FIG. 2 the air compressor portion 14 of the pump comprisesa housing or body member 24 that is attached to a flared flange 26 onthe fuel pump body 12 by means of a crimped or turned over portion 28.It is understood that other means of attaching the air compressor bodyto the body of the fuel pump such as bolts, screws, welding and the likecould also be used. Body 24 could also be made integral with fuel pumpbody 12. Within housing 24 is a diaphragm 30 that is held in position ina diaphragm retaining area 32 on body 24 which is an outturned or flaredportion on the housing generally U-shaped and integrally formedtherewith. The diaphragm is held in a sealed position in retaining area32 by flared or flanged end portions 33 on cylinder 34 and 35 on valveretaining housing member 36. Below the flared end 35 on valve retaininghousing member 36 there is a gasket 38 to provide a seal between thevalve housing member and the diaphragm retaining area 32. Body member 24and the valve housing 36 attached thereto, as well as the upper crimpedportion 28 and diaphragm 30 form an oil reservoir 29 within the bodymember 24.

Cylinder 34 includes an elongated, tubular extension 40 integral withflared ends 33 that receives the sidewalls 42 of slidably piston 44.Piston 44 has a -U-shaped flange at the upper end as at 46 to retain endplate 48 having a plurality of openings 50 therein. Piston 44 also has aplurality of openings as at 51 adjacent the U- shaped flange 46. Thebottom or lower plate 52 of piston 44 is integral with the side walls ofpiston 42 and has a plurality of holes or openings 54 therein. It isunderstood that this lower plate could be made as a separate member andjoined to the piston side wall in any convenient means of attachment;Beneath lower plate 52 and above the diaphragm 30 there is an oil cavity53 formed by the shape of the bottom of-plate 52 and the bottom orflared end 33 of tubular extension 40. The size and shape of cavity 53is determined by the pressure that is necessary to act on diaphragm 30to move said diaphragm into the bottom cavity so that it will be incomplete conformity with the bottom cavity to give maximum pressureoutput.

Adjacent the bottom plate 52 is a valve member 56 that closes theplurality of holes 54. Valve member 56 is seated on upturned seatportions 58 on plate 52 by means of spring 60. Retained within valvemember 56 by a spring 57 is a second valve member 62 that closes inletport 64.

Piston member 44 is actuated by the engine cam 22 through rocker arm 18,which is attached to a central shaft member 66 that connects the fuelpump operating- Valve housing 36 contains an intake valve 74 and anexhaust valve 76. The valves are generally of the type well known in theart. On the intake stroke, or upward stroke of the piston, valvemember75 operates against a spring 77 to allow air into cavity 78 locatedbeneath diaphragm 30. Upon the downward or exhaust stroke of piston 44,exhaust valve member 79 operates against spring 81 to exhaust air fromcavity 78.

FIG. 3 shows another embodiment of the invention similar to theembodiment shown in FIG. 2. Body member 80 of the compressor is formedintegral with the fuel pump 12. The bottom or lowermost portion of body80 has a flange member 82 with steps 84 therein for retaining andaligning diaphragm 86, and flared ends 87 on tubular extension 88 andgasket 90. Diaphragm 86, flared end 87 on tubular extension 88 andgasket 90 are secured to and held in a sealed relationship within a bodycavity 92 by a valve housing or cover plate 94. Valve housing 94 is heldin position on body member 80 by a crimped flange 96. It is understoodthat any convenient locating means or means of attachment could also beused. Tubular extension 88 receives a sidewall 98 of piston member 100.The piston member 100 also has flared end as at 102 at the upper endthereof to retain an end plate 104. End plate 104 has a plurality ofopenings 106 therein. Piston 100 also has a plurality of openings 108adjacent the flared end 102 and has an integral bottom or lower plate110 having a single enlarged hole 112 therein. 7

Located within piston 100 is a valve member 114. Valve member 114comprises a spring biased shaft 116 having a stepped disc shaped closuremember 118 that closes an opening in the center of a rubber disc orplate member 119. An upper head portion 120, also disc shaped, is heldin locked position on shaft 116 by upending the shaft as at 122. Aroundshaft 116 is a spring 124 that bottoms on a disc closure member 126.Spring 124 is biased upwardly by the disc 126 against the head member120 to close the hole in rubber disc 119. Disc member 126 is biased byspring 128 downwardly against the lower plate 110 to close the opening112 by seating on plate 110 and against disc 119. The piston 100 is alsobiased in an upward position or direction by spring 130 and is driven ina downward direction against the spring bias by drive member 132,similar to that of FIG. 2, whereby the drive member is attached to arocker arm 134 in the same manner as previously described in relation toFIG. 2. In addition, the drive member 132 has a spring 136 that acts onthe end plate 104 to provide additional lift or thrust upwardly of therocker arm 134 to assure a positive contact with the rocker arm and cam.

In operation, the two different air compressors as shown in FIGS. 2 and3 are basically the same. There fore, it is understood that thedescription of the operation of the air compressor shown in FIG. 2 willsuffice to explain the operation of the air compressor shown in FIG; 3.The primary difference between the two embodiments is in the valvingmechanism in the bottom plate. In the operation of the air compressor,oil is initially added to the oil reservoir 29 through the rocker armopening and the oil is then generally replenished by'oil splashing fromthe crankcase into the rocker arm opening into the reservoir 29. Ifdesired, a filler hole could also be added in housing 24.

.As cam 22 reaches its highest point, drive member 70 through rocker arm18 moves piston 44 downwardly,

through seat portion 58 and the holes in the bottom plate 54. When thepiston reaches the end of or lowermost point of the downward stroke, therocker arm and drive member 70 through the action of return spring 72moves the piston in an upward direction. As the piston moves upwardly,the volume in cavity 53increases thereby creating a vacuum therein. Thediaphragm at this time also moves upwardly into cavity 53 to anuppermost or highest cavity position as permitted by the shape oftubular extension 40 and the bottom plate 52 that act to form the cavityshape. As the piston continues to move in an upward direction valve 62opens, when the vacuum in the chamber above diaphragm 30 becomes greatenough to overcome the spring force exerted by spring 57, acting on thevalve disc member 62. When the valve opens oil enters the cavity 53through holes 54. The action of the oil through the valves and therespective holes above the cavity prevents aeration on the oil side ofthe diaphragm. This action is the intake stroke of the compressorwherein air is pulled in through valve 76 into cavity 78 below thediaphragm in preparation for the next exhaust stroke. The stroke isapproximately 0.380 in length at a pressure of psi creating a pumpingvolume of 65 in/- min at 1,000 rpm. Y

The air compressor is generally used in air bag suspension systems onautomobiles, these systems not making up part of this invention. The airbag system generally contains a maximum pressure limiting device andupon the air bag reaching that pressure a bypass valve is opened so thatair pumped by the compressor is pumped to the atmosphere until the airbag requires additional air. The pump is a continuous pump that operateswhen the automobile engine operates.

Although our invention has been described in terms of certain specificembodiments, it is to be understood that other forms may be adoptedwithin the scope of the invention.

We claim:

1. In a combination air compressor and fuel pump assembly of the typehaving a common rocker arm for driving the fuel pump and air compressorthe improvement comprising: an oil filled housing adapted to be securedto the fuel pump body; a diaphragm secured within a flanged portion onsaid housing by a cylinder, a valve housing, a gasket, and a flangedportion on said body crimped below the valve housing and gasket; ahollow piston having top and bottom perforated end plates slidablypositioned within said cylinder with said top perforated end plate beingunobstructed to allow oil from the oil filled housing to enter anddischarge through the perforations into and out of said piston; saidcylinder, piston and the upper side of said diaphragm define an oilcavity; whereas the lower side of said diaphragm and valve housingdefine an air cavity; a relief valve within said hollow piston springbiased against a seat on said perforated bottom end plate to close theperforations in said end plate to prevent oil from discharging from theoil cavity during the pumping stroke; an inlet valve positioned withinsaid relief valve that is spring biased so as to close an inlet openingin said relief valve to, along with the relief valve, prevent oil fromdischarging from the oil cavity during the pumping stroke and whichinlet valve allows oil to enter the oil cavity from the oil filledhousing through the inlet opening during the intake stroke to empty theoil cavity and thereby allow the air cavity to be filled, said valvehousing having air intake and discharge valves therein to take in airthrough the air intake valve during the suction stroke through thedischarge valve and discharge air out of the lower cavity during thepump stroke; drive means secured to a rocker arm which drive means is incontact with the top perforated piston end plate to slidably move saidpiston into said cylinder during the pump stroke, and spring meanssurrounding said cylinder which is in contact with the underside of theupper portion of said piston which spring means moves said piston out ofsaid cylinder during the suction stroke.

2. In a combination air compressor and fuel pump assembly as set forthin claim 1; with said piston having an integrally formed perforatedplate at one end, and a second separate plate held within said pistonadjacent the other end by crimped means.

3. A compressor adapted to be driven by an engine cam comprising: ahousing having an end connected to the engine block at a cam porttherein; a diaphragm secured within a flanged portion on said housing bya cylinder, a valve housing, a gasket, and a crimped over portion onsaid body below the valve housing; said housing and diaphragm definingan oil filled reservoir in communication with the endine crankcasethrough the cam port; a piston having perforated end plates slidablypositioned within said cylinder; said cylinder, piston and diaphragmdefine an upper oil cavity; whereas said diaphragm and valve housingdefine a lower air cavity; said perforated end plates on said pistonpermits oil from the reservoir to enter and discharge through theperforations into and out of said piston and oil cavity; a relief valvewithin said piston spring biased against a seat on said piston to closethe perforations in one piston end plate to prevent oil from dischargingfrom the upper oil cavity during the pumping stroke, an inlet valvewithin said relief valve spring biased to close an inlet opening in saidrelief valve to prevent oil from discharging from the upper cavityduring the pumping stroke and allowing oil to enter the upper oil cavityfrom the reservoir through the inlet opening during the intake stroke;said valve housing having air intake and discharge valves therein tointake and discharge air into and out of the lower cavity during therespective intake and pump strokes; and drive means secured to thecommon rocker arm and in contact with the piston end portion oppositesaid diaphragm to slidably move said piston into said cylinder.

1. In a combination air compressor and fuel pump assembly of the typehaving a common rocker arm for driving the fuel pump and air compressorthe improvement comprising: an oil filled housing adapted to be securedto the fuel pump body; a diaphragm secured within a flanged portion onsaid housing by a cylinder, a valve housing, a gasket, and a flangedportion on said body crimped below the valve housing and gasket; ahollow piston having top and bottom perforated end plates slidablypositioned within said cylinder with said top perforated end plate beingunobstructed to allow oil from the oil filled housing to enter anddischarge through the perforations into and out of said piston; saidcylinder, piston and the upper side of said diaphragm define an oilcavity; whereas the lower side of said diaphragm and valve housingdefine an air cavity; a relief valve within said hollow piston springbiased against a seat on said perforated bottom end plate to close theperforations in said end plate to prevent oil from discharging from theoil cavity during the pumping stroke; an inlet valve positioned withinsaid relief valve that is spring biased so as to close an inlet openingin said relief valve to, along with the relief valve, prevent oil fromdischarging from the oil cavity during the pumping stroke and whichinlet valve allows oil to enter the oil cavity from the oil filledhousing through the inlet opening during the intake stroke to empty theoil cavity and thereby allow the air cavity to be filled, said valvehousing having air intake and discharge valves therein to take in airthrough the air intake valve during the suction stroke through thedischarge valve and discharge air out of the lower cavity during thepump stroke; drive means secured to a rocker arm which drive means is incontact with the top perforated piston end plate to slidably move saidpiston into said cylinder during the pump stroke, and spring meanssurrounding saId cylinder which is in contact with the underside of theupper portion of said piston which spring means moves said piston out ofsaid cylinder during the suction stroke.
 2. In a combination aircompressor and fuel pump assembly as set forth in claim 1; with saidpiston having an integrally formed perforated plate at one end, and asecond separate plate held within said piston adjacent the other end bycrimped means.
 3. A compressor adapted to be driven by an engine camcomprising: a housing having an end connected to the engine block at acam port therein; a diaphragm secured within a flanged portion on saidhousing by a cylinder, a valve housing, a gasket, and a crimped overportion on said body below the valve housing; said housing and diaphragmdefining an oil filled reservoir in communication with the endinecrankcase through the cam port; a piston having perforated end platesslidably positioned within said cylinder; said cylinder, piston anddiaphragm define an upper oil cavity; whereas said diaphragm and valvehousing define a lower air cavity; said perforated end plates on saidpiston permits oil from the reservoir to enter and discharge through theperforations into and out of said piston and oil cavity; a relief valvewithin said piston spring biased against a seat on said piston to closethe perforations in one piston end plate to prevent oil from dischargingfrom the upper oil cavity during the pumping stroke, an inlet valvewithin said relief valve spring biased to close an inlet opening in saidrelief valve to prevent oil from discharging from the upper cavityduring the pumping stroke and allowing oil to enter the upper oil cavityfrom the reservoir through the inlet opening during the intake stroke;said valve housing having air intake and discharge valves therein tointake and discharge air into and out of the lower cavity during therespective intake and pump strokes; and drive means secured to thecommon rocker arm and in contact with the piston end portion oppositesaid diaphragm to slidably move said piston into said cylinder.